Fistula treatment device

ABSTRACT

A fistula treatment system comprises a guide such as a guide coil  1101  which is adapted to extend partially around a tissue tract and an implant element  1102 . The implant element  1102  is activated to draw tissue surrounding the tract inwardly.

CROSS-REFERENCE TO RELATED APPLICATIONS

This application is a continuation-in-part of International ApplicationNo. PCT/EP2016/061944, filed on May 26, 2016, which claims the benefitof priority of European Application No. 15169640.8, filed on May 28,2015. This application also claims the benefit of priority of EuropeanApplication No. 16201270.2, filed Nov. 29, 2016, and EuropeanApplication No. 16174951.0, filed Jun. 17, 2016, all of which areincorporated by reference herein in their entireties.

INTRODUCTION

The invention relates to a device and a system for the treatment ofperianal fistulas.

A perianal fistula is an artificial tunnel that, in the majority ofcases, develops from an infection that begins within a blocked analgland. If the infection cannot be cleared from the anal gland an abscessforms and the infection burrows though the sphincteric muscles and exitsat the buttocks integument. Patients experience pain associated with thetract and associated abscesses and suffer faecal and blood dischargefrom the fistula tract. Perianal fistulas may also result fromgastro-intestinal diseases such as Crohn's disease, ulcerative colitis,colorectal cancers and their associated treatment and complications dueto rectal fissures and trauma.

The global incidence of perianal fistula is 2 per 10,000 population.Over 100,000 fistula procedures are performed between the United Statesand Western Europe each year. Thirty percent of the procedures performedare reoperations due to treatment failure contributing to a significantpreventable cost to the healthcare systems.

Given the inadequate treatment options and poor surgical outcomes thereis a defined clinical need for a more effective perianal treatmentdevice.

There is currently no single “gold standard” technique that a surgeoncan perform to effectively cure a perianal fistula and not render thepatient incontinent. A common fistula treatment is a fistulotomyprocedure. A fistulotomy involves the dissection of the sphinctericmuscles and the laying open of the fistula tract. Fistulotomies have arelatively high cure rate, however, this procedure results in a highrisk of faecal incontinence.

From a patient's point of view, many are happy to assume the risk ofincontinence in order to resolve the painful fistula tract. However,this is obviously not an ideal treatment pathway and for many patientpopulation groups the secondary outcome is far from acceptable.

Another commonly used fistula treatment methodology is the use of aseton. Setons are used as a sphincter sparing technique and is simply asuture or vascular strap that is passed through the tract of the fistulaand the rectum and tied in a loop. The seton maintains tract patencyallowing the infection in the fistula tract to drain, help the tractconstrict in length and may cure the tract. If the tract is not cured bythe seton the physician can perform a fistulotomy. This approach oftrying to preserve the sphincter with setons has been used for over 2500years and is still the preferred method used by surgeons today.

In an effort to provide a non-destructive perianal fistula treatmentvarious glues and plugs have been developed and introduced to colorectalsurgeons in the past 20 years. However, these techniques are not verysuccessful and their use is not widespread. Such glues which areinjected into the fistula tract generally become brittle and are notable to occlude the tract for a long enough period to fully heal, faecesre-enter the tract resulting in abscess formation and refistulisation.Physicians often attempt to treat perianal fistulas with glues and plugseven though there may only be a 10 percent chance of effectivenessbecause it is a sphincter sparing technique and they can always resortto a seton and eventual fistulotomy if all fails.

Attempts have also been made to use plugs to occlude perianal fistulatracts. For example, US2005/004926A describes a plug-like fistulaclosure device with an attached flexible application string which alsoserves to evacuate liquids out of a fistula. However, generally theplugs fail because they become extruded from the tract, allowing faecesto enter the tract resulting in reinfection, abscess formation andrefistulisation.

There is therefore a need for an improved method and device for thetreatment of perianal fistulas.

STATEMENTS OF INVENTION

According to the invention there is provided a fistula treatment systemcomprising a guide which is adapted to extend at least partially arounda tissue tract. Also provided is an implant element which is adapted totrack the pathway of a guide.

In one embodiment the implant element has a tracking configuration inwhich the implant element follows the pathway of the guide and anactivated configuration, the implant in the activated configurationbeing adapted to draw tissue surrounding a tract inwardly.

The implant element in some cases comprises an anchor.

The anchor may comprise at least one barb.

The anchor may have a collapsed delivery configuration and a radiallyextending configuration.

The anchor may comprise a plurality of filaments.

In some cases the anchor is located at a distal end of the implantelement.

In one embodiment the implant element forms a coil in the collapseddeployed configuration.

The coil in one case has a substantially uniform lateral extent along alength thereof.

The coil may be tapered along a length thereof.

In one embodiment the implant element is an activatable element. Theactivatable element may have a collapsed delivery configuration, adeployed configuration and an activated configuration. The activatableelement may comprise an expansile element such as a balloon, or a foam.

In some embodiments the implant element comprises a shape memorymaterial such as Nitinol.

In one case the implant element is at least partially bioabsorbable.

In some embodiments there are a plurality of implant elements.

In some embodiments the guide comprises a guide coil.

The guide coil may have a substantially uniform lateral extent along alength thereof.

The guide coil may be tapered along a length thereof.

In some cases the coil comprises a rail for the implant element.

The coil may be solid or hollow.

In one case the guide coil comprises a sharp distal tip.

In some embodiments the system comprises a drain or seton having ananchoring feature for anchoring the drain/seton in situ.

The anchoring feature may be provided at a compression zone or region ofthe seton.

In some cases the anchoring feature comprises a step or projection onthe seton, such as one or more of a knot, a barb or a quill.

The seton may be hollow or solid.

In some cases the seton has a plurality of peripheral holes.

In some embodiments the shape of seton in cross section is selected fromone or more of round, oval, star and cross.

The seton may comprise multiple elements. The elements of the seton maybe braided.

In some cases at least a portion of the seton is bioabsorbable. In onecase the seton is of differential bioabsorption. A proximal portion ofthe seton may be bioabsorbable.

The seton may extend from the implant.

In some cases at least a portion of the implant is bioabsorbable and atleast a portion of the seton is configured to bioabsorb in advance ofbioabsorption of the implant.

In another case the seton is bioabsorbable and the implant is notbioabsorbable.

The invention also provides a method for treating a perianal fistulacomprising the steps of:—

-   -   providing an implant;    -   inserting the implant into the bulk tissue of the sphincteric        muscle complex adjacent to the fistula; and    -   using the implant to draw tissue surrounding the fistula        inwardly.

The method may further comprise:—

-   -   activating the implant to draw tissue surrounding the tract        inwardly.

The method may comprise anchoring the implant in the tissue.

In some cases the implant is anchored prior to activation of theimplant.

The invention further provides a method for closing a fistulacomprising:—

-   -   providing a guide and an implant element;    -   advancing the guide to extend at least partially around a tissue        tract;    -   advancing the implant element to follow the track of the guide;        and    -   withdrawing the guide leaving the implant element in place        surrounding the tissue tract.

The method may further comprise activating the implant element to drawtissue surrounding the tract inwardly. The method may further compriseanchoring the implant element in tissue, prior to activating the implantelement.

According to the invention there is also provided a perianal fistulatreatment device comprising an implant coil having an anti-rewindfeature. The anti-rewind feature may be selected from one or more of:

-   -   a positive feature such as a barb, arrowhead or fishhook-like        feature;    -   a negative feature such as a trough, a slot or a groove, and    -   a surface feature such as surface roughening.

In one embodiment the device comprises a tapered portion which isconfigured for insertion into bulk tissue surrounding a fistula and adriver interface portion which is configured for engagement with adriver for rotation of the coil to draw tissue surrounding a fistulainwardly.

The invention also provides a drainage seton having an anchoring featurefor anchoring the seton in situ. In some cases the anchoring feature isprovided at a compression zone or region of the seton.

In some embodiments the anchoring feature comprises a step or projectionon the seton, such as one or more of a knot, a barb or a quill.

The invention further provides a fistula treatment system comprising afistula treatment device of the invention and a driver implement forrotation of the coil to draw tissue surrounding a fistula inwardly. Inone embodiment the driver implement comprises a driver coil which isconfigured for engagement with the driver interface of the implant coil.

In some cases at least a portion of the outer surface of the driver coilis lubricious.

There may be engagement features on the driver coil and/or the implantcoil for temporarily locking the driver coil to the implant coil fordelivery of the implant coil.

The invention also provides a fistula treatment system comprising afistula treatment device of the invention and a tissue stabilisingdevice for stabilising the mucosal tissue for delivery of the implant.

In some embodiments the stabilising device comprises a hollow elementattached to the delivery mechanism and surrounding the implant prior todelivery. The hollow element may be spring loaded or otherwise to applypressure to the mucosal surface.

In one embodiment a leading surface of the hollow element thatinterfaces to the mucosal surface interacts with the mucosal surface toprevent rotation and/or twisting of the mucosal lining. The hollowelement may comprise features such as needles for penetration into themucosal surface.

The invention also provides a method for treating a perianal fistulacomprising the steps of:—

-   -   providing a tapered coil;    -   inserting the coil into the bulk tissue of the sphincteric        muscle complex adjacent to the fistula; and    -   rotating the coil to draw tissue surrounding the fistula        inwardly.

In some embodiments the method comprises:—

-   -   providing a drainage seton;    -   embedding the seton in the sphincter muscle complex; and    -   leading the seton so that the distal end of the seton protrudes        through the external    -   opening of a fistula tract.

Also provided is a method for treating a perianal fistula comprising thesteps of:—

-   -   providing an implant coil with a delivery interface region;    -   providing a delivery device with an implant coil interface        region;    -   inserting the implant coil into the delivery device; and    -   rotating the implant coil using the delivery device.

In some cases, after insertion of the implant coil, the delivery deviceis released from the coil.

The method may further comprise:—

-   -   providing a drainage seton;    -   attaching the seton to the coil; and    -   leading the seton externally of the fistula.

The method may comprise:—

-   -   providing a drainage seton;    -   embedding the seton in the sphincter muscle complex; and    -   leading the seton so that the distal end of the seton protrudes        through the external    -   opening of a fistula tract.

According to the invention there is provided a perianal fistulatreatment device comprising an implant coil having a tapered portionwhich is configured for insertion into bulk tissue surrounding a fistulaand a driver interface portion which is configured for engagement with adriver for rotation of the coil to draw tissue surrounding a fistulainwardly.

In one embodiment the driver interface portion of the coil has asubstantially uniform lateral extent along a length thereof.

In one case the coil has a leading end, a transition region, and atrailing end, the tapered portion of the coil extending from the leadingend to the transition region and the driver interface portion extendingfrom the transition region.

Preferably the tapered portion of the coil decreases in lateral extentbetween the leading end and the transition region.

In one case the leading end of the tapered portion has a pointed tissueinsertion tip.

In one embodiment at least the driver interface portion of the coil issolid.

Alternatively at least the driver interface portion of the coil ishollow.

In one case the coil is solid.

Alternatively the coil is hollow.

In some cases the shape of the coil in cross section is selected fromone or more of round, oval, triangular, multifaced and ribbon.

In one embodiment at least a portion of the coil is bioabsorbable.

In one case the fistula treatment device further comprises a drainageseton.

The seton may extend from the coil.

In one case the seton is hollow.

In one case the seton is solid.

In one embodiment the seton has a plurality of peripheral holes.

The shape of seton in cross section in some cases is selected from oneor more of round, oval, star and cross.

In one embodiment the seton comprises multiple elements. The elements ofthe seton may be braided.

In one case at least a portion of the seton is bioabsorbable.

In one case the seton is of differential bioabsorption. In oneembodiment a proximal portion of the seton is bioabsorbable, forexample, to facilitate removal of a remainder of the seton. In anotherembodiment a distal portion of the seton is bioabsorbable to facilitateclosure of the enternal opening of the fistula prior to full absorptionof the seton.

In one embodiment at least a portion of the coil is bioabsorbable and atleast a portion of the seton is configured to bioabsorb in advance ofbioabsorption of the coil.

The invention also provides a fistula treatment system comprising afistula treatment device and a driver implement for rotation of the coilto draw tissue surrounding a fistula inwardly.

In one case the driver implement comprises a driver coil which isconfigured for engagement with the driver interface of the implant coil.

In one embodiment the driver coil has a substantially uniform lateralextent along a length thereof for engagement with the correspondingdriver interface portion of the implant coil.

In one case the driver coil is hollow and the corresponding driverinterface portion of the implant coil is solid.

In another case the driver coil is solid and the corresponding driverinterface portion of the implant coil is hollow.

The invention also provides a perianal fistula treatment devicecomprising an implant coil which is configured for insertion into bulktissue surrounding a fistula and being rotatable to draw tissuesurrounding the fistula inwardly and a drainage seton extending from thetapered coil.

In one case the coil is tapered.

The invention also provides a perianal fistula treatment devicecomprising a tapered coil and a drainage seton mounted to and extendingfrom the tapered coil.

The invention also provides a perianal fistula treatment devicecomprising an implant coil which is configured for insertion into tissuesurrounding a fistula and a drainage seton wherein at least a portion ofthe seton is bioabsorbable.

In one embodiment the seton is of differential bioabsorption.

In one case a proximal portion of the seton is bioabsorbable tofacilitate removal of a remainder of the seton.

The tapered coil is preferably configured for insertion at the site ofthe internal opening of a fistula and being rotatable to draw bulktissue, including sphincteric muscle, surrounding the fistula inwardly.

In one case the coil has a leading end and a trailing end, the coildecreasing in lateral extent between the leading and trailing ends. Theleading end may include a pointed tissue insertion tip.

In one embodiment the device comprises a seton attachment feature.

The attachment feature may be selected from one or more of:—a protrusionsuch as a ball-shape; a hook; a cleat; a butt joint; or a bond such as athermal and/or adhesive bond.

In one embodiment the centering element has a recess or hole forreception of a seton. The seton may be bonded or fixed to the recess orhole in the centering feature, for example by adhesive and/or thermalbonding, and/or crimping.

In another embodiment the device comprises a delivery mechanismattachment feature.

In one case the device comprises a centre element which extends at leastpartially along a longitudinal axis of the coil.

The centre element may extend from the trailing end of the coil towardsthe leading end of the coil.

The centre element may extend to a distance beyond the leading end ofthe coil.

The centre element may comprise a seton attachment feature and/or adelivery mechanism attachment feature.

In one case the seton is hollow.

The seton may have a plurality of peripheral holes.

The shape of the seton in cross section may be selected from one or moreof round, oval, star and cross.

In one case the seton comprises multiple elements which may be braided.

In one case the coil is solid. In another case the coil is hollow.

The shape of the coil in cross section may be selected from one or moreof round, oval, triangular, multifaced and ribbon.

The invention also provides a fistula treatment device comprising atapered coil which is configured for insertion into bulk tissuesurrounding a fistula and being rotatable to draw tissue surrounding thefistula inwardly, the coil having a centering element that extends atleast partially along a longitudinal axis of the coil.

The device may further comprise a drainage seton mounted to andextending from the tapered coil.

In one case the coil has a leading end and a trailing end, the coildecreasing in lateral extent between the leading and trailing ends. Theleading end may include a pointed tissue insertion tip.

In one embodiment the device comprises a seton attachment feature.

In one embodiment the device comprises a delivery mechanism attachmentfeature.

In one case the centering element extends from the trailing end of thecoil towards the leading end of the coil.

In one embodiment the centering element comprises a seton attachmentfeature. The attachment feature may be selected from one or more of:—aprotrusion such as a ball-shape; a hook; a cleat; a butt joint; or abond such as a thermal and/or adhesive bond.

The centering element may have a recess or hole for reception of aseton. The seton may be bonded or fixed to the recess or hole in thecentering feature, for example by adhesive and/or thermal bonding,and/or crimping.

In one embodiment the centering element comprises a delivery mechanismattachment feature. The seton may be hollow or solid. The seton may havea plurality of peripheral holes. The seton in cross section may beselected from one or more of round, oval, star and cross. The setoncomprises multiple elements. The elements may be braided. The coil maybe solid or hollow. The shape of the coil in cross section may beselected from one or more of round, oval, triangular, multifaced andribbon.

The invention also provides a system comprising a fistula device of theinvention and a delivery device for the perianal fistula treatmentdevice.

In one embodiment the delivery device comprises a hollow element throughwhich the tapered coil is delivered.

In one embodiment the delivery device comprises a solid element overwhich a hollow tapered coil is delivered.

In one embodiment the delivery device comprises a hollow element throughwhich a straight cylindrical coil is delivered.

In one embodiment the delivery device comprises a solid element overwhich a hollow straight cylindrical coil is delivered.

The hollow delivery element may comprise a coil.

In one embodiment the delivery device comprises a rail for the deliveryof the tapered coil. The rail and the coil may comprise interengagabletrack features.

The invention also provides a method for treating a perianal fistulacomprising the steps of:—

-   -   providing a tapered coil;    -   inserting the coil into the bulk tissue of the sphincteric        muscle complex adjacent to the    -   fistula; and    -   rotating the coil to draw tissue surrounding the fistula        inwardly.

In one embodiment the method further comprises:

-   -   providing a drainage seton;    -   attaching the seton to the coil;    -   using the seton to provide apposition of the coil and mucosal        surface prior to delivery of the coil; and    -   leading the seton externally of the fistula;

In one case the method comprises embedding the seton in the sphinctermuscle complex and leading the seton so that the distal end of the setonprotrudes through the external opening of a fistula tract.

The invention also provides a method for treating a perianal fistulacomprising the steps of:—

-   -   providing an implant coil with a delivery interface region;    -   providing a delivery device with an implant coil interface        region;    -   inserting the implant coil into the delivery device; and    -   rotating the implant coil using the delivery device.

In one embodiment, after insertion of the implant coil, the deliverydevice is released from the coil.

The method may further comprise:—

-   -   providing a drainage seton;    -   attaching the seton to the coil; and    -   leading the seton externally of the fistula.

The method may comprise:—

-   -   providing a drainage seton;    -   embedding the seton in the sphincter muscle complex; and    -   leading the seton so that the distal end of the seton protrudes        through the external opening of a fistula tract.

The perianal fistula treatment device has the advantages of:

-   -   effective healing of the fistula tract;    -   preservation of continence; and    -   improved healing time.

The device preserves the patient's continence by protecting thesphincteric muscles from division. The device is securely anchored intothe fistula tract, effectively sealing the tract and preventing faecalmatter from entering the internal opening during the healing process.

The device allows any remaining abscess materials to drain from thetract during the healing process. The device may be integrated into thetissue over the healing process, and may be ultimately absorbed as thetract is healed.

The invention removes variability due to surgeon skill by providing astandardised technique for treating perianal fistulas.

The device facilitates gathering and apposing sphincter muscle tissueallowing repair of a defect in the muscle bulk.

A single ended drainage seton is attached to allow drainage of a fistulatract post closure of the internal opening of a tract.

A delivery mechanism is provided with attachment feature(s) to interfacewith the tapered coil and seton.

The tapered coil may have an anchor for a single ended seton.

The tapered coil may be of metal, bioabsorbable polymer, bioabsorbablemetal.

The drainage seton may be made from any suitable materials includingbioabsorbable, synthetic.

The system may be capable of delivering multiple coils.

The system may be capable of delivering a tapered coil located at thedistal portion of an endoscope.

The method for treating an anal fistula may include any or all of thefollowing steps:

-   -   using seton for location/tension/mucosal wall apposition prior        to delivering;    -   using a delivery mechanism to deliver a closure device to repair        a defect in the bulk tissue of the sphincteric muscle complex;    -   delivering a closure device below the surface of the mucosal        lining of the rectum at the dentate line into bulk tissue to        allow remodelling of the mucosal lining over the site of        delivery; and    -   embedding a seton in the sphincter muscle complex with the        distal end protruding through the external opening of a fistula        tract in order to allow drainage and healing of a fistula tract.

Aspects of the present disclosure may be directed to a method oftreating a perianal fistula with an implant. The implant may have aproximal end and a distal end, and the perianal fistula may have aninternal opening from the rectum, an external opening in an externalsurface of a buttocks, a fistula tract extending between the internalopening and the external opening, and fistula tissue surrounding thefistula tract. The method may include:

-   -   engaging the distal end of the implant about the internal        opening to compress fistula tissue via the implant,    -   sealing closed the internal opening of the fistula tract while        leaving open the external opening of the fistula tract, and    -   embedding the proximal end of the implant in the fistula tissue        such that none of the implant may be exposed to the rectum.

The sealing may include sealing against pressure of up to 150 mmHg.

The sealing may include sealing against pressure of up to 200 mmHg.

The compressing may include compressing fistula tissue in an opposedconfiguration.

The method may further include facilitating a passageway through theexternal opening to allow for draining.

The method may further include positioning a drainage member within thefistula tract.

At least a portion of the drainage member may extend from a locationwithin the fistula tract and through the external opening.

The compressing may include progressively compressing fistula tissuesuch that a compression force imparted to fistula tissue via the distalend of the implant may be less than a compression force imparted tofistula tissue via the proximal end of the implant.

Following the compressing, a majority of the fistula tract may remainopen.

Aspects of the present disclosure may be directed to a method oftreating a perianal fistula with an implant. The implant may have aproximal end and a distal end, and the perianal fistula may have aninternal opening from the rectum, an external opening in an externalsurface of a buttocks, a fistula tract extending between the internalopening and the external opening, and fistula tissue surrounding thefistula tract. The method may include:

-   -   forming a perianal sinus by closing the internal opening with        the implant.

The forming the perianal sinus may include rotating the implant toadvance the implant through fistula tissue toward the external opening.

The rotating of the implant may cause compression of the fistula tissue.

The method may further include drawing fistula tissue radially inwardly,a first region of fistula tissue may be drawn radially inwardly to agreater extent than at least a second region of fistula tissue, and thefirst region may be closer to the internal opening than the secondregion.

The implant may comprise a tapered portion, the forming the sinus mayinclude drawing tissue radially inwardly via the tapered portion, aproximal end of the tapered portion having a diameter less than a distalend of the tapered portion, the implant being deployed such that theproximal end may be closer to the internal opening than the distal end.

The method may further include positioning a drainage member within thefistula tract, at least a portion of the drainage member may extend froma location within the fistula tract and through the external opening.

The method may include embedding the proximal end of the implant in thefistula tissue.

The forming of the perianal sinus may further include forming a sealagainst pressure of up to 150 mmHg.

Aspects of the present disclosure may be directed to a method oftreating a perianal fistula with an implant. The implant may have aproximal end and a distal end, and the perianal fistula may have aninternal opening from the rectum, an external opening in an externalsurface of a buttocks, a fistula tract extending between the internalopening and the external opening, and fistula tissue surrounding thefistula tract. The method may include:

-   -   contacting the fistula tissue with the implant about the        internal opening, the implant may include a coil having a        plurality of coil loops extending between the proximal end and        the distal end, at least a portion of the coil may be tapered        along a length of the coil between the proximal end and the        distal end;    -   rotating the implant into fistula tissue to advance the distal        end of the implant toward the external opening, causing a        diameter of at least a portion of the fistula tract to be        reduced via the tapered portion; and    -   facilitating drainage through the external opening after the        implant is in place.

The method may further include compressing fistula tissue via theimplant, the compressing may include progressively compressing fistulatissue such that a compression force imparted to fistula tissue via thedistal end of the implant may be less than a compression force impartedto fistula tissue via the proximal end of the implant.

The method may further include compressing fistula tissue so as to closethe internal opening while maintaining the external opening open.

The facilitating drainage through the external opening may includepositioning a drainage member in the fistula tract, at least a portionof the drainage member may extend from a location within the fistulatract and through the external opening.

The at least one of the implant or the drainage member may bebioabsorbable.

Both of the implant and the drainage member may be bioabsorbable, and arate of absorption of the implant may be faster than a rate ofabsorption of the drainage member.

Both of the implant and the drainage member may be bioabsorbable, and arate of absorption of the drainage member may be faster than a rate ofabsorption of the implant.

A method of closing an opening in tissue may include:

-   -   delivering a helical implant into tissue such that a plurality        of helical loops of the implant may pass through tissue        surrounding the opening and may compress the tissue radially        inwardly; and    -   fixing a drain element relative to the implant such that after        the implant is delivered the drain element may extend from        within the opening to a location outside of the opening, the        drain element may be configured to facilitate fluid drainage        from the opening along the drain element.

The method may further include drawing tissue around the openingradially inwardly toward a center of the implant, a first region oftissue may be drawn radially inwardly to a greater extent than at leasta second region of tissue.

The implant may include a tapered coil portion tapering toward aproximal end of the coil.

The method may further include sealing closed only one end of theopening.

The method may further include engaging a tapered distal section of adelivery device with an inner surface of the implant.

The method may further include engaging a non-tapered distal section ofa delivery device with an external surface of the implant.

An implant for treating a fistula may comprise:

-   -   a shaft having a proximal end, a distal end, and a plurality of        coil loops; and    -   a plurality of barbs positioned on the shaft, each of the        plurality of barbs may be located distally of a proximal-most        coil loop of the plurality of coil loops;    -   the shaft may include a tapered portion.

The shaft may further include a non-tapered portion.

Each of the plurality of barbs may be located distally of thenon-tapered portion.

The non-tapered helical coil portion may extend along a minority of alength of the shaft between the proximal end and the distal end.

Each of the plurality of barbs may be a pre-formed, positive,anti-rotation feature.

An implant for treating a fistula may comprise:

-   -   a shaft having a proximal end and a distal end and forming a        helical coil therebetween, the helical coil may have:        -   a tapered portion comprising a first plurality of coil            loops; and        -   a non-tapered portion comprising a second plurality of coil            loops.

The tapered portion may include more coil loops than the non-taperedportion.

A longitudinal length of the non-tapered portion may be smaller than alongitudinal length of the tapered portion.

The implant may include a channel extending along a surface of at leastsome of plurality of coil loops.

The implant may further include a drainage member having a deployedconfiguration in which the drainage member may be fixed relative to theimplant.

The implant may further include a driving abutment positioned betweenthe proximal end and the distal end.

A system for treating a fistula may comprise:

-   -   an implant extending between a proximal end and a distal end,        the implant may include:        -   a helical coil having a plurality of coil loops including a            tapered portion; and    -   a driver coil extending between a proximal end and a distal end,        the driver coil and the helical coil of the implant may have a        common pitch; and    -   in a first configuration, a section of the driver coil may be        engaged with a portion of the implant, and in a second        configuration, the section of the driver coil may be disengaged        from the portion of the implant.

The implant may include a channel extending along a surface of at leastsome of plurality of coil loops.

The driver coil may be a non-tapered coil.

The implant may further include a non-tapered portion.

The implant may further include a driving abutment located along thenon-tapered portion.

The non-tapered portion may extend along a minority of a length of theimplant between the proximal end and the distal end of the implant.

In the first configuration, one of the section of the driver coil andthe portion of the implant may be received within the other of thesection of the driver coil and the portion of the implant.

The portion of the implant may be the non-tapered portion.

The system may further include a drainage member having a deployedconfiguration in which the drainage member may be fixed relative to atleast one of the implant or the driver coil.

A kit for closure of an opening in human tissue may comprise:

-   -   an implant having a shaft forming a helical coil and having a        proximal end and a distal end, at least a portion of the helical        coil may have a tapered coil portion; and    -   a longitudinally extending drain member.

The helical coil may further include a non-tapered coil portion.

The tapered coil portion may include a first plurality of coil loops andthe non-tapered coil portion may include a second plurality of coilloops, the first plurality of coil loops may include a greater number ofcoil loops than the second plurality of coil loops.

A longitudinal length of the non-tapered helical coil portion may besmaller than a longitudinal length of the tapered helical coil portion.

A driving abutment may be positioned between the proximal end and thedistal end.

At least one of the implant or the drain member may be bioabsorbable.

Both of the implant and the drain member may be bioabsorbable, and arate of absorption of the implant may be faster than a rate ofabsorption of the drain member.

Both of the implant and the drain member may be bioabsorbable, and arate of absorption of the drain member may be faster than a rate ofabsorption of the implant.

BRIEF DESCRIPTION OF THE DRAWINGS

The invention will be more clearly understood from the followingdescription of an embodiment thereof, given by way of example only, withreference to the accompanying drawings, in which:

FIG. 1 is a cross-sectional view of an anatomy and disease stateaddressed by the invention;

FIG. 2 is a cross-sectional view of the treatment device of theinvention being delivered through the fistula tract;

FIG. 3 is cross-sectional view of the device at a point of apposition tothe mucosal surface at the site of the internal opening of the fistulatract;

FIG. 4 is cross-sectional view of the device partially delivered throughthe mucosal surface and into the sphincter muscle complex;

FIG. 5 is cross-sectional view of the device fully delivered into thesphincter muscle complex and detached from the delivery mechanism;

FIG. 6 is a plan view illustrating the internal opening of a fistulatract at the mucosal surface;

FIG. 7 is a plan view illustrating the device located at the internalopening of a fistula tract in apposition with the mucosal surface;

FIG. 8 is a plan view illustrating the device partially deliveredthrough the mucosal surface and beginning to gather tissue internally tothe device resulting in narrowing of the fistula internal opening;

FIG. 9 is a plan view illustrating the device further delivered throughthe mucosal surface and into the sphincter muscle complex with furthergathering of tissue internally to the device resulting in additionalnarrowing of the fistula internal opening;

FIG. 10 is a plan view illustrating the device completely deliveredsub-mucosally and entirely into the sphincter muscle complex with tissueinternal to the device resulting in complete closure of the fistulainternal opening;

FIG. 11 is a front view of an embodiment of a perianal fistula treatmentdevice;

FIG. 12 is a plan view of the device of FIG. 11;

FIG. 13 is a side view of the device of FIGS. 11 and 12;

FIG. 14 is a front view of another fistula device with pointed tip;

FIG. 15 is a side view of the device of FIG. 14;

FIG. 16 is a plan view of the device of FIGS. 14 and 15;

FIG. 17 is an isometric view of the device of FIGS. 14 to 16;

FIG. 18 is an isometric view of a further fistula treatment device withpointed tip and centre feature;

FIG. 19 is a front view of the device of FIG. 18;

FIG. 20 is a side view of the device of FIGS. 18 and 19;

FIG. 21 is a plan view of the device of FIGS. 18 to 20;

FIG. 22 is an isometric view of a device with pointed tip and centrefeature and seton;

FIG. 23 is an isometric view of a device with pointed tip and centreseton attachment feature with attached seton;

FIG. 24 is a cross-sectional view of a cross shape seton;

FIG. 25 is a cross-sectional view of an oval shape seton;

FIG. 26 is a cross-sectional view of a round shape seton;

FIG. 27 is a cross-sectional view of a round hollow shape seton;

FIG. 28 is an isometric view of a round hollow perforated embodiment ofa seton;

FIG. 29 is a cross-sectional view of a hollow star shape seton;

FIG. 30 is a cross-sectional view of a star shape seton;

FIG. 31 is an isometric view of a star shape hollow perforatedembodiment of a seton;

FIG. 32 is a cross-sectional view of a cross shape seton;

FIG. 33 is a cross-sectional view of a multi-braid embodiment of aseton;

FIG. 34 is an isometric view of an oval cross-section embodiment of theclosure coil device;

FIG. 35 is an isometric view of a ribbon type tapered coil of a perianalfistula treatment device;

FIG. 36 is an isometric view of a triangular cross-section embodiment ofa tapered coil;

FIG. 37 is an isometric view of a multi-faced cross-section embodimentof the tapered coil;

FIG. 38 is an isometric view of a hollow delivery mechanism of thetapered coil;

FIG. 39 is an isometric view of a solid coil to be delivered by thehollow delivery mechanism of FIG. 38;

FIG. 40 is an isometric view of the hollow delivery mechanism of FIG. 38and the solid coil of FIG. 39 in place;

FIG. 41 is an isometric view of a solid core delivery mechanism with ahollow coil in place;

FIG. 42 is an isometric view of a rail support structure for deliveringa mating coil;

FIG. 43 is an isometric view of a coil that mates with the supportstructure of FIG. 42;

FIG. 44 is an isometric view of the combination of a coil and rail typedelivery mechanism;

FIG. 45 illustrates the component parts of the system;

FIG. 46 illustrates the delivery of the system through the fistula tractprior to deployment of the coil;

FIG. 47 illustrates the position of the coil prior to deployment;

FIG. 48 illustrates a ball type centre feature seton attachmentmechanism;

FIG. 49 illustrates a hook type centre feature seton attachmentmechanism;

FIG. 50 illustrates a cleat type centre feature seton attachmentmechanism;

FIG. 51 illustrates a hollow type centre feature seton attachmentmechanism;

FIG. 52 illustrates a hollow type centre feature seton attachmentmechanism;

FIG. 53 illustrates a swage type centre feature seton attachmentmechanism;

FIG. 54 illustrates a crimp type centre feature seton attachmentmechanism;

FIG. 55 illustrates a thermal bond type centre feature seton attachmentmechanism;

FIG. 56 illustrates a butt joint type centre feature seton attachmentmechanism;

FIG. 57 is an isometric view of a coil with a partially straightsection;

FIG. 58 and FIG. 59 are isometric views of a hollow coil deliverymechanism interfaced with a solid coil;

FIG. 60 and FIG. 61 are isometric views of a solid coil deliverymechanism interfaced with a hollow coil;

FIGS. 62 and 63 are isometric views of another fistula treatment deviceaccording to the invention;

FIGS. 64 and 65 are plan views of the device of FIG. 62;

FIG. 66 is an isometric view of a delivery coil for use with the fistulatreatment device;

FIG. 67 is an isometric view of the delivery coil engaged with a fistulatreatment device;

FIG. 68 is a view of a drainage seton according to the invention;

FIG. 69 is a view of another drainage seton of the invention;

FIG. 70 is a view of a further drainage seton of the invention;

FIG. 71 is a view of another drainage seton;

FIGS. 72 and 73 illustrate the fixing of a drainage seton into positionin a tissue tract;

FIGS. 74 and 75 are views of a stabilising device according to theinvention;

FIG. 76 is a diagram of a fistula treatment system according to theinvention;

FIG. 77 is a perspective view of a guide coil of the system;

FIG. 78 shows the system in a delivery configuration;

FIG. 79 illustrates an implant element in an activated configuration;

FIG. 80 is a diagram of a distal end of a delivery coil and an implantelement having an anchor;

FIG. 81 shows the delivery coil in another configuration in which theanchor is exposed;

FIGS. 82 and 83 illustrate another anchor;

FIGS. 84 and 85 illustrate a further anchor;

FIG. 86 illustrates another guide and an implant element;

FIG. 87 illustrates deployment of the implant element of FIG. 86;

FIGS. 88 and 89 show another guide and an implant element with a sharpdistal tip;

FIG. 90 is a diagram of another implant according to the invention;

FIG. 91 shows the implant of FIG. 90 in a deployed and activatedconfiguration;

FIG. 92 is a diagram of a further fistula closure system of theinvention in a delivery configuration;

FIG. 93 shows the implant element of FIG. 92 in an activatedconfiguration;

FIG. 94 is a diagram of an implant delivery system according to theinvention;

FIG. 95 shows an implant being delivered from the delivery tube of FIG.94;

FIGS. 96 and 97 are views similar to FIGS. 94 and 95 of another implantelement;

FIG. 98 is an enlarged view of a delivery system for another implant;

FIGS. 99 to 102 illustrate the deployment of another Implant elementaround a fistula; and

FIGS. 103 and 104 are diagrams of a further fistula treatment systemaccording to the invention.

DETAILED DESCRIPTION

The device is capable of one or more of the following:

-   -   accommodating varied fistula tract physiology;    -   occluding and sealing the internal opening of the tract;    -   preventing faecal matter re-infecting the tract;    -   preserving sphincteric function;    -   enhancing fistula tract healing; and    -   facilitating drainage during healing.

The perianal fistula treatment device ensures sparing of the sphincter,occluding of the fistula tract internal opening, and promotion ofdrainage and tissue healing.

The device consists of a head with anchoring and sealing mechanismswhich is secured in the tissue tract and prevents re-infection of thewound. A tail section provides seton-like drainage and preventsre-abscessing due to premature closure of the skin site.

The anchoring and sealing mechanism of the device consists of a taperedcoil. The coil geometry is designed to pull tissue together as is itdeployed into the sphincter muscle complex, resulting in a strong anchorbut also, importantly, an effective compressive seal preventingreinfection of the fistula tract and close tissue approximation toenhance tissue healing.

The perianal fistula treatment device preserves sphincteric andanatomical conditions and functions, prevents re-fistulisation, andimproves healing time over the current treatment methods. The deviceconsists of a tapered coil and a drainage seton. There may be acentering alignment feature. A delivery mechanism is also described. Thecoil may be led into the fistula tract by the drainage seton andcentered into the tract by means of the centering feature. The largerdiameter of the tapered coil is abutted against the tissue surface,surrounding the internal opening of the fistula tract with adequatemargin. The delivery mechanism rotates the coil until it is justsubmucosal positioned. The coil closes the fistula internal opening bycompressing the tract's surrounding tissue inwardly such that the tissueis brought within close approximation creating a seal impermeable toforeign materials and promoting tissue growth across the closelyapproximated fistula tract. The drainage seton provides a conduit todrain any abscess and remaining or newly formed exudate and fluids fromthe fistula tract throughout the time of the healing process. Thecentering feature insures the coil device is placed easily into thefistula tract and the outer coil is placed within the adequate marginssurrounding the fistula tract and acts as a securing mechanism for thedrainage seton.

The following numerals are used in the drawings:

-   -   1. Rectum    -   2. Anus    -   3. Internal Sphincter Muscle    -   4. External Sphincter Muscle    -   5. Dentate Line    -   6. Fistula Tract    -   7. Internal Opening    -   8. External Opening    -   9. Anal Verge    -   10. Levator Ani Muscle    -   11. Coil    -   12. Seton    -   13. Seton Distal End    -   14. Seton Attachment    -   15. Coil Distal Tip    -   16. Delivery Mechanism Member    -   17. Delivery Mechanism Interface    -   18. Delivery Mechanism    -   19. Internal Opening Mucosal Surface    -   20. Musocal Surface    -   21. Internal Opening    -   22. Compressed Sphincter Muscle Tissue    -   23. Coil    -   24. First End    -   25. Second End    -   26. Medial Portion    -   27. Coil Member    -   28. Pointed Tip    -   29. Delivery Mechanism Interface Feature    -   30. First End    -   31. Second End    -   32. Coil Member    -   33. First End    -   34. Second End    -   35. Pointed Tip    -   36. Centre Feature    -   37. Coil Member    -   38. Delivery Mechanism Interface Feature    -   39. Second End    -   40. Delivery Mechanism Interface Feature    -   41. First end    -   42. Pointed Tip    -   43. Coil Member    -   44. Centre Seton Feature    -   45. First End    -   46. Second End    -   47. Pointed Tip    -   48. Delivery Mechanism Interface Feature    -   49. Coil Member    -   50. Centre Feature    -   51. Seton Attachment Feature    -   52. Drainage Seton    -   53. Drainage Seton End    -   54. Cross Shape Seton Cross Section    -   55. Oval Seton Cross Section    -   56. Round Seton Cross Section    -   57. Outer Wall Hollow Round Seton Cross Section    -   58. Round Hollow Cross Section    -   59. Hollow Perforated Seton    -   60. First End    -   61. Second End    -   62. Hollow Centre Section    -   63. Perforation    -   64. Hollow Star Seton Cross Section    -   65. Solid Star Seton Cross Section    -   66. Hollow Perforated Star Seton    -   67. First End    -   68. Second End    -   69. Hollow Feature    -   70. Perforation    -   71. Cross Shape Seton Cross Section    -   72. Braided Seton Cross Section    -   73. Integument    -   200. Implant coil    -   201. Coil straight section    -   202. Coil tapered section    -   203. Transition from straight to tapered section    -   204. Hollow delivery assembly    -   205. Hollow delivery coil    -   206. Solid coil implant    -   207. Coil straight section    -   208. Coil tapered section    -   209. Interface    -   210. Solid delivery assembly    -   211. Hollow coil implant    -   212. Solid delivery coil    -   213. Coil straight section    -   214. Coil tapered section    -   220. Leading end    -   221. Trailing end

FIG. 1 illustrates an anal fistula tract 6, which is an abnormalconnection between the rectum 1 and the integument of the buttocks 73.The internal opening 7 of the fistula is located at the mucosal surface20 of the rectum 1. The fistula tract 6 may generally originate at thedentate line and pass through the sphincteric muscle complex whichconsists of the internal sphincter muscle 3 and external sphinctermuscle 4. The external opening 8 of the fistula tract 6 is located atthe integument surface of the buttocks 73.

FIG. 2 shows the device consisting of a tapered coil 11, drainage seton13, and delivery mechanism 18 being drawn through the fistula tract bymeans of tension applied to second end of drainage seton 13.

The tapered coil 11 is brought into apposition to the mucosal tissuewall of the rectum 20 as shown in FIG. 3. The coil is centered on theinternal opening of the fistula tract 7 at the dentate line 5 viatension applied to the second end 13 of the drainage seton 12 and thesupport of the bioabsorbable mechanism 18 interface 17.

The driver mechanism 17 delivers the coil 11 through the mucosal lining20 of the rectum 1 via rotatory or other means (FIG. 4). The distal tip15 of the coil 11 punctures through the musocal lining surface 20 andengages initially with the internal sphincter muscle 3 surrounding theinternal opening 7 of the fistula tract 6.

FIG. 45 illustrates the system component parts. The delivery mechanisminterface feature 38 of the coil 11 is attached to the deliverymechanism member 16 of the delivery mechanism 18. The drainage seton 12is attached to a coil centering feature 50 via the seton attachmentfeature 14.

FIG. 5 illustrates the coil 11 completely delivered through and past themucosal surface 20 and into the sphincter complex consisting of theinternal 3 and external 4 sphincter muscles. The delivery mechanisminterface 17 located distally on the delivery mechanism member 16detaches from the tapered coil 11 and the delivery mechanism 18 isremoved from the surgical field.

The mechanism of action of the delivery of the tapered coil results insphincter muscle complex tissue being drawn into the centre of the coil11 construct. The mechanism of action is illustrated in FIGS. 6-10.

FIG. 6 illustrates a plan view of an internal opening 21 of a fistulatract 6 located at the surface of the musical lining of the rectum 20 atthe dentate line 5. FIG. 7 shows the closure coil 11 being brought intoapposition to the musical surface 20 and being centred on the fistulatract 7 internal opening 21. As the closure coil 11 is delivered throughthe mucosal surface 20 and into the internal sphincter muscle 3 thesphincter muscle tissue begins to be gathered into the centre of theclosure coil 11. FIG. 9 illustrates further delivery of the closure coil11 resulting in an increased mass of sphincter muscle tissue beinggathered internally in the coil. FIG. 10 illustrated complete deliveryof the closure coil 11 entirely past the mucosal surface 20 andcompletely into the sphincter muscle complex including the internal 3and external 4 sphincter muscles. The complete delivery of the coil 11results in closure of the internal opening 21 of the fistula tract 6 bymechanism of gathering and compression of sphincter muscle tissue. Thismechanism as described allows both the sphincter muscle tissue to knittogether, and the mucosal surface to remodel to cover the site ofdelivery over a period of time, eventually resulting in completeresolution of the sphincter muscle defect associated with the internalopening of the fistula tract.

Referring to FIGS. 11 to 13 there is illustrated a tapered coil 12 whichhas a leading end 24 and a trailing end 25. The coil is in this caseconical and decreases in lateral extent between the leading and trailingends.

The implant is a coiled body structure. The leading end of the implantis the largest coil and initially surrounds the tissue defect withappropriate margin. As the implant is advanced the leading end providesa large surface area to effectively anchor the implant. Each subsequentcoil provides (adds to) the anchoring and compression function. Thesmallest coil towards the trailing end provides the highest amount oftissue compression. As the implant is turned into the tissue each coilfurther compresses the captured tissue toward the center of the tissuedefect, thus effectively completely compressing the surrounding tissueinwardly. The close approximation of tissue allows for the tissue toheal together. This compression provides an effective seal against thepressures generated in the rectum and prevents entering of passingfaeces into the fistula tract thus preventing re-infection. The smallerdiameters of the implant coils retain the captured tissue fromseparating and prevents the breakdown of the healing process or foreignmaterial from entering the tissue defect. This is a major advantage oversutures and suture based surgical techniques such as the advancementflap (dermal flap) and the LIFT procedures.

The compression ensures close approximation of tissue throughout thecenter of the implant. At the most proximal surface the closeapproximation of tissue provides support to the healing mucosal liningof the rectum over the implant and tissue defect. Thus the healingtissue is fully supported by the implant during the healing process andis capable of surviving pressures of 150 mmHg and upwards of 200 mmHgwhich can be generated in the rectum.

The coil is delivered submucosal (at a predetermined depth) below thesurface of the mucosa. This is to ensure that there is a full mucosalseal at the rectal mucosa surface to provide for a bacterial sealbarrier. With the implant just below the surface the tissue is drawninwards for complete compression and supports the mucosa healingprocess.

As the implant is turned into the tissue the compression becomes greateralong the depth of the coil (progressive compression) and the length ofthe tract captured internal of the implant is compressed completely.This close approximation of tissue aids in the healing process.

Referring to FIGS. 14 to 17 it will be noted that in this case thetapered coil 12 has a pointed tissue insertion tip 28. The coil 12 alsohas a delivery mechanism interface feature 29.

FIGS. 18 to 21 illustrate another tapered coil 12 which also has apointed tissue insertion tip 35 and a delivery mechanism interfacefeature 38. In this case the coil also has a centering feature 36. Thecentering feature 36 passes through the centre of the fistula tract andallows attachment of the drainage seton. The centering feature 36 allowscentering of the coil in a concentric fashion to the fistula tractinternal opening.

It will be appreciated that a coil device with a centering feature suchas the centering feature 36 illustrated in FIGS. 18 to 21, with orwithout an attached seton, may be used to close fistula openings thatmay commonly occur in other areas of the body, such as: biliary (createdduring gallbladder surgery, connecting bile ducts to the surface of theskin), cervical (either an abnormal opening into the cervix or in theneck), craniosinus (between the space inside the skull and a nasalsinus), enterovaginal (between the bowel and vagina), faecal or anal(the faeces is discharged through an opening other than the anus),gastric (from the stomach to the surface of the skin), metroperitoneal(between the uterus and peritoneal cavity), umbilical (between the naveland gut). These fistulas may be:—blind also known as a sinus (open onone end only, but connects to two structures); complete (has bothexternal and internal openings); horseshoe (connecting the anus to thesurface of the skin after going around the rectum); or incomplete (atube from the skin that is closed on the inside and does not connect toany internal structure).

FIG. 22 illustrates a coil device with a centre seton feature 44. Inthis embodiment the coil, centre feature and drainage seton areconstructed from a single continuous monolithic structure.

FIG. 23 illustrates a coil which has a centre feature 50 with a setonattachment feature 51 at the distal end. A drainage seton 52 is attachedto the feature 50.

It will be appreciated that the tapered coil may be of any suitableshape in transverse cross section. Some examples are illustrated inFIGS. 34 to 44. For example, the coil may be round, oval, triangular,multifaced or ribbon-like. In some cases the coil may be hollow.

The coil may be intended for subsequent removal or may be bioabsorbable.

Typical materials for the coil include

-   -   Bioabsorbable magnesium (including MgFe and other magnesium        alloys) would be a material of choice because it offers the        strength of stainless steel and similar metals, yet is        bioabsorbable. MgFe alloys are well studied and have been used        in medical products.    -   PLA) and PLGA (poly(lactic-co-glycolic acid)) are bioabsorbable        polymers and would be a material of choice as they are commonly        used bioabsorbable materials and have been well studied and used        in medical products for over 70 years.    -   The coil may also be constructed from other common materials        used for suture applications

A bioabsorbable tapered coil would be beneficial to treatment ofperianal fistulas due to the body's natural tendency to reject foreignmaterials.

The system of the invention also comprises a delivery device for theperianal fistula treatment device.

The delivery device may comprise a hollow element such as illustrated inFIG. 38 through which the tapered coil is delivered. The hollow deliveryelement may comprise a coil. FIG. 39 illustrates a solid coil to bedelivered by a hollow delivery element of FIG. 38 and FIG. 40 shows thehollow delivery element with the solid coil in place.

The system consists FIG. 40 of a hollow delivery element FIG. 38 thatcontains (houses) the implantable element FIG. 39. The implantableelement FIG. 39 is housed in the delivery element FIG. 38 during therotational delivery process. Once the delivery element FIG. 38 hasreached the desired delivery position, it is uncoupled from theimplantable element FIG. 39 and then rotated in the opposite directionof the direction of delivery (most commonly counter clockwise), leavingthe implantable element FIG. 39 in place of the tissue bulk.

It will be appreciated that the system may be reversed with a hollowcoil delivered over a solid delivery element.

In some cases the delivery device comprises a rail for the tapered coil.The rail and the coil may have interengagable features. Some examplesare illustrated in FIGS. 42 to 44.

The rail system FIG. 44 consists of an outer implantable coil elementFIG. 42, and an inner support rail element FIG. 43. The two elementsinterlock. The system FIG. 44 is rotated (most commonly in a clockwisedirection) to the desired tissue depth. Upon the system FIG. 44 reachingthe desired tissue depth, the elements are uncoupled FIG. 42 and theinner support rail is reversed out of the tissue bulk by rotationopposite in direction to insertion (commonly counter clockwise), leavingbehind the outer implantable coil element FIG. 42 in place surrounding,compressing and closing the fistula tract.

It will be appreciated that the system may be reversed with an innerimplantable coil delivered over an outer support rail.

Ball Attachment FIG. 48:

The centre feature may have a ball feature along the shaft to aid inanchoring a seton that may be tied or looped around the centre feature.The ball provides a back stop where the knotted or looped seton will notdetach from the centre feature.

Hook Attachment FIG. 49:

The centre feature may have a hook feature along the shaft to aid inanchoring a seton that may be tied or looped around the centre feature.The hook provides a back stop where the knotted or looped seton will notdetach from the centre feature.

Cleat Attachment FIG. 50:

The centre feature may have a cleat feature along the shaft to aid inanchoring a seton that may be tied or looped around the waist of thecleat feature. The cleat provides a back stop where the knotted orlooped seton will not detach from the centre feature.

Internal to Centre Feature FIGS. 51 and 52

The centre feature may be hollowed as in FIG. 51 and the seton may beplaced in the hollowed portion. It may be glued or heat staked as shownin FIG. 52 or crimped as shown in FIG. 53.

Butt Joint FIG. 54:

The seton may be attached by a butt joint as shown in FIG. 55. Thecentre feature and seton are inserted into a tubular element withopposite ends facing each other as in FIG. 55. The three components maybe joined by heating, glue as shown in FIG. 55, or by crimping/swagingas shown in FIG. 54. The join may have multiple crimp points along thetubular element to securely attach the seton and centre feature.

Thermal Bond FIG. 56

The seton and centre feature may be thermally bonded/joined together asin FIG. 56, where both materials are made of a material with similarglass transition temperatures (Tg) and brought to their Tg and allowedto flow together creating a secure junction.

It will be appreciated that the embodiments of this system may alsoincorporate features such as previously described, including, but notlimited to, a centre feature, a seton attachment feature, an integrateddrainage seton and an integrated sharp tip located on the drive rail.

The seton 12 is used as a guidance and positioning mechanism and oncethe device is implanted serves as a means of fistula tract drainage. Theseton 12 may be constructed of bioabsorbable materials, tissue healingenchantment properties, infection control agents and be constructed ofpart or composite of these materials.

After the fistula tract preparation, the seton 12 is attached usingstandard surgical technique to the existing surgical probe, suture, orseton already in place in the fistula tract. Once the seton 12 isattached, the system is pulled through the fistula tract proximally(towards the physician) until the coil device is adjacent to the tissuewall (rectal wall). The seton 12 ensures that the outer leading coil iscentred around the outside of the fistula tract. Tension may be appliedto the seton 12 as the coil is advanced into the tissue to aid inadvancement and to maintain a centred position around the fistula tract.

The seton 12 is attached to the central portion of the coil 11. With thecoil knitting together the sphincteric muscle and closing the fistulatract's internal opening the seton 12 maintains the proximal portion ofthe fistula tract's patency to facilitate drainage of any abscess, pus,and new accumulation of bodily fluids to prevent infection occurrence.The seton 12 prevents the tract from closing in on itself proximal ofany fluid accumulation and acts as a conduit allowing material drainagebetween the wall of the tract and the outer wall of the seton 12. Theseton 12 may also have a central lumen with tangential drainage holesentering from the external wall of the seton 12. The seton 12 may beconstructed with a multi surface external wall to create channels andoptimize the fluid drainage and prevent the fistula tract wall fromoccluding drainage around the seton. The seton 12 may be constructed ofpart or all elements as described and illustrated in FIGS. 24 to 33.

The seton 12 is constructed of materials that are strong enough to allowfor surgical placement in the fistula tract. The seton 12 may beconstructed of materials that are non-absorbable and meant to be removedat a later time. Alternatively, the seton 12 may be made of materialsthat bioabsorb throughout and upon completion of the fistula tracthealing processes (examples include magnesium, PLA, PLGA). The seton 12may be constructed of or include anti-infection agents to preventinfection of the fistula tract (silver ions, antibacterial agents). Theseton 12 may be constructed of materials that aid in tissue growth (stemcell, collagen matrix). The seton 12 may be constructed of part or allelements as described.

The seton may be of any suitable shape in cross section such as round,oval, cross shape, star or braid as illustrated in FIGS. 24 to 26 andFIGS. 30, 32, 33. In all cases the seton may be hollow as illustrated inFIGS. 27, 28, 29 and 31 to further enhance drainage. The seton may haveperipheral holes as illustrated in FIGS. 28 and 31 to provide forincreased drainage effectivity. The holes allow additional surfaces ofdrainage, by increasing drainage surface area/channels the fluid drainsmore quickly and reduces the chance that any of the channels will becomeoccluded and prevent fluid drainage at the same moment in time.

FIG. 46 illustrates the delivery of the system through the fistula tractprior to deployment of the coil. The seton, attached to the centrefeature allows the coil to be drawn into apposition against the mucosalwall, and located concentric to the fistula tract internal opening.

FIG. 47 illustrates the position of the coil prior to deployment anddemonstrates the effect of the centering feature in combination with theseton in positioning the coil concentrically around the fistula tractinternal opening. (Dimensions ‘x’ being equal).

As noted above, one or other or both of the coil and seton may comprisebioabsorbable materials.

Typical materials for the coil include:

-   -   Bioabsorbable magnesium (including MgFe and other magnesium        alloys) is one material of choice because it offers the strength        of stainless steel and similar metals, yet is bioabsorbable.        MgFe alloys are well studied and have been used in medical        products.

Synthetic bioabsorbable materials may include PLA and PLGA (poly(lactic-co-glycolic acid)) (PLGA, PCL, Polyorthoesters, Poly(dioxanone),Poly(anhydrides), Poly(trimethylene carbonate), Polyphosphazenes), andor natural bioabsorbable materials may include fibrin, collagen,chitosan, gelatin, Hyaluronan are bioabsorbable polymers and would be amaterial of choice as they are commonly used bioabsorbable materials andhave been well studied and used in medical products for over 70 years.

For example, companies such as Ethicon market a number of such productswith different absorption rates such ashttp://www.ethicon.com/healthcare-professionals/products/. Absorbablepolymer materials are also available from medical material companiessuch as Zeus, seehttp://www.zeusinc.com/advanced-products/absorv-bioabsorbables.

Typical materials for the seton include:

-   -   Bioabsorbable magnesium (including MgFe and other magnesium        alloys) is one material of choice because it offers the strength        of stainless steel and similar metals, yet is bioabsorbable.        MgFe alloys are well studied and have been used in medical        products.    -   Synthetic bioabsorbable materials may include PLA and PLGA        (poly(lactic-co-glycolic acid)) (PLGA, PCL, Polyorthoesters,        Poly(dioxanone), Poly(anhydrides), Poly(trimethylene carbonate),        Polyphosphazenes), and or natural bioabsorbable materials may        include fibrin, collagen, chitosan, gelatin, Hyaluronan are        bioabsorbable polymers and would be a material of choice as they        are commonly used bioabsorbable materials and have been well        studied and used in medical products for over 70 years.

In one case both the coil and the seton are bioabsorbable, and the setondegrades prior to the degradation of the coil. This may be achieved in anumber of different ways, such as the seton being of a differentbioabsorbable material to the coil.

For example the coil implant may be constructed of PLLA which degradesslowly, typically within 18 to 36 months depending on formulation, crosssection, and surface modifications, and the Seton drain may beconstructed of PLGA (85L/15G) which typically degrades “faster” in 1 to2 months depending on formulation, cross section, and surfacemodifications

Another method of altering the time of degradation (degradation(absorption) properties) is by providing a reduced cross sectional area,more porosity, less crystallinity, more reactive hydrolytic groups inthe backbone, more hydrophilic end groups, and/or more hydrophilicbackbone.

In one case, the seton begins to absorb 5 weeks post-surgicalimplantation. This is variable depending upon the healing time of thepatient, with full healing usually occurring within a 5 to week period.By way of example the coil implant may remain for a period of at least10 weeks after healing and may degrade over a 6 to 18 month time periodfrom the date of implantation.

Advantageously, the closure mechanism of the device is maintained duringthe entire healing process. In some cases the coil remains in situ towithstand rectal pressures and maintain closure of internal tractopening for at least 10 weeks to prevent re-opening of the tract.

The coil implant may remain in place longer to allow full healing of theinternal opening of the fistula tract. The seton drain may degrade at afaster rate compared to the coil implant so long as the seton drain isin place for a long enough time for all remaining abscess and infection,to drain from the fistula tract and any side branches. It isadvantageous that the seton drain absorbs faster than the coil so thatthe patient does not have any visually remnant feature of the device orthoughts of fistula. The seton is not needed for as long a period as thecoil implant, with the seton drain absorbing faster than the implant,the patient will not have to return to the surgeon for removal duringthe internal opening healing process.

Also, the implant remains in place for a long enough period of time(e.g. greater than 1 week) to allow remodelling of the defect in themucosa and formation of a mucosal layer. This mucosal layer acts as abacterial seal preventing reinfection of the tract from entering offasces. The reformation of the musical layer in conjunction with thesphincter muscle closure mechanism prevents fasces entering the tract.

The implant coil and draining seton may be doped or loaded with healingand antimicrobial agents (such as stem cell, silver ions, silverparticles, antibiotics, antibacterial agents and the like).

The seton may be of differential bioabsorption wherein the seton isabsorbed at a different rate along its length.

The seton may be of differential bioabsorption wherein the distalportion of the drain absorbs more quickly than the proximal portion.This differential absorption of the seton results in the seton remainingattached to the coil via the proximate portion until fully absorbed.Advantageously, this allows for the external opening to close and removethe chance of the seton being pulled out through the external opening.

The seton may also be of differential bioabsorption wherein the proximalportion of the seton absorbs more quickly—in this case the anchoringmechanism of the closure device with relation to the seton could bebroken at an earlier time than the full seton absorption allowing theseton to be removed (by the patient or doctor or naturally fall out)through the external opening.

In both differential absorption embodiments, the entire seton would haveto remain in place for full healing (and drainage) time of the tract(e.g. 10 weeks).

The bioabsorbable materials used in the construction of the implantcoil, or drainage seton, or both, can be both natural or syntheticpolymers such as those listed below.

Natural Polymers

-   -   Fibrin    -   Collagen    -   Chitosan    -   Gelatin    -   Hyaluronan

Synthetic Polymers

-   -   PLA, PGA, PLGA, PCL, Polyorthoesters    -   Poly(dioxanone)    -   Poly(anhydrides)    -   Poly(trimethylene carbonate)    -   Polyphosphazenes

The selection of the material used can be made whilst taking thefollowing factors into account.

Factors that Accelerate Polymer Degradation:

-   -   More hydrophilic backbone.    -   More hydrophilic endgroups.    -   More reactive hydrolytic groups in the backbone.    -   Less crystallinity.    -   More porosity.    -   Smaller device size.

The implant coil of the invention may be delivered by a number oftechniques. In one case the coil is delivered by a coil deliverymechanism. In this case, the implant coil may have an interface regionfor interfacing with the delivery mechanism.

A perianal fistula treatment device may comprise an implant coil havinga tapered portion which is configured for insertion into bulk tissuesurrounding a fistula. The implant coil may have a driver interfaceportion which is configured for engagement with a driver implement forrotation of the coil to draw tissue surrounding a fistula inwardly. Theadvantages of such an implant coil are:

-   -   Ability to be delivered deep into the sphincter muscle complex        allowing for greater anchoring and sphincter muscle apposition        at the muscle defect    -   Ability to disengage from the delivery mechanism in a spiral        nature, allowing reversing of the delivery mechanism through the        same tract as delivery preventing further damage to the tissue    -   Prevents the mucuosa of the rectum being pulled down towards the        sphincter muscle complex    -   Ability to be delivered through and past the anoderm resulting        in lower pain due to interference with the nerve endings of the        anoderm    -   Prevention of bacterial tracking by delivering deep sub        mucosally allowing a new mucosal lining to form at the fistula        internal opening

One such implant coil 200 is illustrated in FIG. 57 and comprises atapered section 202 and a driver interface portion which in this case isprovided by straight coil section 201 which has a substantially uniformlateral extent along a length thereof. The implant coil 200 has aleading end 220, a transition region 203 and a trailing end 221. Thetapered portion 202 of the coil extends from the leading end 220 to thetransition region 203 and the driver interface portion 201 extends fromthe transition region 203 to the trailing end 221. It will be notedthat, as described in other embodiments, the tapered portion of the coildecreases in lateral extent between the leading end 220 and thetransition region 203. The leading end 220 may have a pointed tissueinsertion tip as illustrated, for example, in FIGS. 14 to 17.

The implant is a coiled body structure. The leading end of the implantis the largest coil and initially surrounds the tissue defect withappropriate margin. As the implant is advanced the leading end providesa large surface area to effectively anchor the implant. Each subsequentcoil provides (adds to) the anchoring and compression function. Thesmallest coil towards the trailing end provides the highest amount oftissue compression. As the implant is turned into the tissue each coilfurther compresses the captured tissue toward the center of the tissuedefect, thus effectively completely compressing the surrounding tissueinwardly. The close approximation of tissue allows for the tissue toheal together. This compression provides an effective seal against thepressures generated in the rectum and prevents entering of passingfaeces into the fistula tract thus preventing re-infection. The smallerdiameters of the implant coils retain the captured tissue fromseparating and prevents the breakdown of the healing process or foreignmaterial from entering the tissue defect. This is a major advantage oversutures and suture based surgical techniques such as the advancementflap (dermal flap) and the LIFT procedures.

The compression ensures close approximation of tissue throughout thecenter of the implant. At the most proximal surface the closeapproximation of tissue provides support to the healing mucosal liningof the rectum over the implant and tissue defect. Thus the healingtissue is fully supported by the implant during the healing process andis capable of surviving pressures of 150 mmHg and upwards of 200 mmHgwhich can be generated in the rectum.

The coil is delivered submucosal (at a predetermined depth) below thesurface of the mucosa. This ensures that there is a full mucosal seal atthe rectal mucosa surface to provide for a bacterial seal barrier. Withthe implant just below the surface the tissue is drawn inwards forcomplete compression and supports the mucosa healing process.

As the implant is turned into the tissue the compression becomes greateralong the depth of the coil (progressive compression) and the length ofthe tract captured internal of the implant is compressed completely.This close approximation of tissue aids in the healing process.

In this and other embodiments the implant body is in the form of an opentapered coil body (for example, without a cross bar or other centeringfeature) in which the leading edge, (into the muscle) is of a largerdiameter than the trailing edge, (rectum surface). The trailing portionis of smaller diameter than the leading portion. The coil is of openform, therefore there is no inward protrusion at either the proximal nordistal end of the body. This open form factor enables the implant to bedriven into the tissue body to a pre-determined depth (depending on thetaper) which results in progressive tissue compression.

At least the driver interface portion of the implant coil is solid andin some cases all of the implant coil is solid. Alternatively, asdescribed above and below, the implant coil or at least part thereof maybe hollow.

In this embodiment, preferably the treatment device also includes aseton of the type described above. In some cases the seton is notmounted or attached to the implant coil during delivery but may beattached so as to extend from the coil when the coil is in situ. In somecases the seton may be embedded in the sphincter muscle complex and leadso that the end of the seton protrudes through the external opening ofthe fistula tract.

The implant is delivered using any suitable delivery device asdescribed. In one case the delivery device comprises a driver implementwhich interfaces with the implant coil and is used to rotate the coil todraw tissue surrounding a fistula inwardly. The driver implementpreferably interfaces with the driver interface of the implant coil.

In some cases the driver implement comprises a driver coil which isconfigured for engagement with the driver interface of the implant coil.The driver coil may have a substantially uniform lateral extent along alength thereof for engagement with the corresponding driver interfaceportion of the implant coil.

In one embodiment as illustrated in FIGS. 58 and 59 a driver coil 205 ishollow for interfacing with the interface portion 201 of the implantcoil.

FIGS. 58 and 59 illustrate an assembly 204 in which a solid implant coil206 is delivered by a straight hollow delivery coil 205. The coilimplant 206 has a straight profile section 207 and a tapered section208. The straight profile section 207 fits within the internal channelof the delivery coil 205 up to the interface 209, whereby the hollowcoil 205 is rotated which in turn rotates the implant coil 206 fordelivery.

The hollow sections of the delivery coil in all cases may comprise asingle turn, multiple turns or part thereof or the entire construct.

FIGS. 60 and 61 illustrate an assembly 210 in which a hollow implantcoil 211 is delivered by a straight solid delivery coil 212. The coilimplant 211 has a straight profile section 213 and a tapered section214. The straight solid delivery coil 212 fits within the internalchannel of the hollow coil implant 211 up to the interface 215, wherebythe solid delivery coil 212 is rotated which in turn rotates the hollowcoil implant 211 for delivery.

The straight sections of the coil in all cases may comprise a singleturn, multiple turns or part thereof.

The hollow sections of the implant coil in all cases may comprise asingle turn, multiple turns or part thereof or the entire construct.

The delivery system has the following advantages:

-   -   Ability to follow the tract of the implant coil allowing deep        delivery to the sphincter muscle complex allowing for greater        anchoring and sphincter muscle apposition at the muscle defect    -   Ability to disengage and retract in a spiral nature, reversing        through the same tract as delivery preventing further damage to        the tissue    -   Prevents the mucuosa of the rectum being pulled down towards the        sphincter muscle complex    -   Enables the implant to be delivered through and past the anoderm        resulting in lower pain due to interference with the nerve        endings of the anoderm    -   Prevention of bacterial tracking by delivering deep sub        mucosally

These delivery mechanisms may be coupled to a manually operated, triggeroperated user interface or similar.

In current techniques for treating a fistula a surgeon identifies theexternal opening of the fistula tract and carefully inserts a probethrough the external opening, through the fistula tract and through theinternal opening of the fistula. The probe is then extended back throughthe rectum and a localisation seton or suture is attached to the end ofthe probe which is then drawn back through the rectum and the fistulatract until it exits through the external opening of the fistula tract.The localisation seton loop is then tied off.

The implant and delivery system of the invention is compatible with thisknown current technique. In the invention the probe or the localisationseton may be used to guide the leading end of the implant coil and/orthe drainage seton.

The implant body in some cases is in the form of an “open” tapered coilbody in which the distal edge (leading edge, into the muscle) is of alarger diameter than the proximal edge (trailing edge, rectum surface),the proximal portion is of smaller diameter than the distal portion. Thecoil is of open form, therefore there is no inward protrusion at eitherthe proximal nor distal end of the body. The open form factor enablesthe implant to be driven into the tissue body to a pre-determined depth(depending on the taper which results in progressive tissuecompression).

The open coil design allows for the mucosal layer to heal over the topof the implant, and the implant supports the healing of the mucosallayer, by preventing the pressure from opening the tract, and compromisefreshly healed mucosa layer. With the implant below the mucosa it doesnot interfere with external rectal surface and interact with faeces thatmay drag the implant out of its purchase or lend to tract infectionalong its body. Thus, the implant is suitable for submucosal deliverywhich facilitates the formation of a continuous mucosal surface over thesite of implantation.

The implant in some cases has anti-movement (anti-rewind) features toprevent the rotational movement of the implant in the counter-clockwisemotion. Typically, the implant is driven into the tissue body in aclockwise motion consistent with the usual direction of driving fixationmedical devices. However, it will be appreciated that the implant mayalso be driven into the tissue in the counter clock-wise direction. Theanti-rewind features facilitate the forward driving motion into thetissue body in a clock-wise motion to be effortless during delivery butprovide resistance to prevent the implant from working itself out orunwinding during the course of natural wound healing and normalphysiological forces experienced day to day of the patient's life.

The anti-rewind features may include one or more of:

-   -   Positive feature such as a barb, fishhook, arrowhead or the like        (such as features 302 of the implant illustrated in FIGS. 62 to        65). Such positive barb type features may be added in the X, Y,        or Z plane to enhance the fixation of the implant;    -   Negative features such as trough features along the body of the        implant, such trough features may be one or more of a square        trough, a lead in trough, and/or a square back trough;    -   V-Lock type, quills may be incorporated along the body of the        implant. The quills may be shaped to facilitate ease of entry        into tissue but does not allow the implant to move in the        opposite direction. The quill may lay fat upon insertion and        then become exposed if moved in the opposite direction. A        multiple of such quills increases the surface area (friction) of        the implant body and prevents the implant from re-winding;    -   Surface modification/surface area enhancing. The surface of the        implant body may be modified to increase the surface area to        increase the friction interaction between the implant and the        tissue it is implanted in.        -   Surface roughening mechanical:            -   May include sandblasting, micro stamping (impression on                material)        -   Surface treatment chemical:            -   May include soaking (being exposed to) in a chemical                agent that roughens the implant body surface            -   May include chemical photo etching        -   Surface treatment in manufacturing process:            -   The tooling of a moulded implant design may have                positive features that when the implant is removed from                the mould, rough features are left on the body of the                implant        -   Surface “pillar” like gecko feet (Setae) Biomimicry:

As described above, a driver coil may be used to insert the implant. Thedriver coil (such as the coil 404 illustrated in FIG. 66) may haveadvantageous pitch 402 and diameter 403 dimensions to minimise tissuebinding during the delivery of the implant coil.

In addition, the driver coil surface 405 may be constructed so as tohave a lubricious nature (e.g. by means of a coating or surfacetreatment or other) in order to minimise the torque requirementassociated with the tissue friction during delivery of the implant coiland during retraction of the delivery coil.

The coiled section of the delivery coil may include features totemporarily lock or fasten to the implant prior to and during implantdelivery. This provides a positive interface between the implant and thedelivery mechanism, to prevent premature implant detachment and relateddelivery issues.

When the implant has been delivered to the correct location and depththe delivery mechanism detaches/disengages from the implant and isremoved from the anatomy.

The driver coil may have an interface to the implant which allowspositive (interlocking) when the driver coil is turned in a clockwisedirection and negative (i.e. disengagement) interaction when the drivercoil is turned in an anti-clockwise direction (or vice versa). Thus whenthe implant has been delivered to the tissue by means of a clockwisedriver coil motion, the driver coil may then turn in an anti-clockwisedirection, disengage from the implant, and exit (or ‘back out’) from thetissue.

The implant may be attached to the delivery coil by a mechanism thatprevents the implant becoming dislodged from the delivery coil prior tocomplete delivery. Thus, the implant coil is prevented from prematurelydetaching from delivery coil.

The internal support structure of the implant coil may have a positivefeature (peak) that locks into a negative (valley) feature on theimplant. There maybe be several features of this type to enhance thelocking grip.

The inverse of this arrangement may also be implemented in which apositive feature is provided on the implant and a negative feature is apart of the driving mechanism.

Alternatively or additionally, the implant may be attached to theinternal opening of the implant driver by friction/interferencefit/surface roughness. The driver col may be hollow and accept a solidimplant or the driver may be solid and inserted into the hollow portionof the implant.

The cross section of the driver coil may be a channel or slot ratherthan closed circular. A coil with such a cross section may be moreeasily manufacturable. It may also allow the incorporation of internal(to the driver coil) locking features to interface with the implant.

The implant is interfaced to the driving mechanism such as a drivercoil. In one case the interface comprises a flare or step that abutsagainst the driving mechanism. One such flare or step 301 is illustratedin FIGS. 62 to 65. Such a flare provides the push point of the implantand transfer of force to drive the implant into the tissue body.

The flare may also act as a barb or anti-rewind feature allowing onlyone way (e.g. clockwise) motion which in one case is forward motion(clockwise motion driven into the tissue body) and prevents the implantfrom moving in a backwards motion (unwinding/counter clockwise).

Such a barb feature may be achieved by having the flare surface areagreater than the driving coil interface surface area.

The flare may be positioned anywhere along the implant body that isoptimal for the implant driving force, driver attachment coupling,and/or anti motion control (anti-rewind can be clockwise or anticlockwise).

It will be appreciated that as an alternative to such locking featureson the implant coil similar features may be provided on the engagementsurfaces of the delivery coil.

The implant is in some cases in the form of a coiled body structure. Thedistal end of the implant is the largest coil, and the distal endinitially surrounds the tissue defect with appropriate margin. As theimplant is advanced the distal portion provides a large surface area toeffectively anchor the implant (each subsequent coil provides (adds to)the anchoring and compression function). The smallest proximal coilprovides the highest amount of tissue compression. As the implant isturned into the tissue each coil further compresses the captured tissuetoward the centre of the tissue defect, thus effectively completelycompressing the surrounding tissue inwardly. The close approximation oftissue allows for the tissue to heal together. This compression providesan effective seal against the pressures generated in the rectum andprevents entering of passing faeces into the fistula tract thuspreventing re-infection. The smaller diameters of the implant coilsretain the captured tissue from separating and prevents the breakdown ofthe healing process or foreign material from entering the tissue defect.This is the advantage over sutures and suture based surgical techniquessuch as the advancement flap (dermal flap) and the LIFT procedures.

The compression ensures close approximation of tissue throughout thecentre of the implant. At the most proximal surface the closeapproximation of tissue provides support to the healing mucosal liningof the rectum over the implant and tissue defect. Thus the healingtissue is fully supported by the implant during the healing process andis capable of surviving pressures of 150 mmHg and upwards of 200 mmHgwhich are generated in the rectum.

Preferably, the coil is delivered submucosal (at a predetermined depth)below the surface of the mucosa. This ensures there is a full mucosalseal at the rectal mucosa surface to provide for a bacterial sealbarrier. With the implant just below the surface the tissue is drawinwards for complete compression and supports the mucosa healingprocess.

As the implant is turned into the tissue the compression becomes greateralong the depth of the coil (progressive compression) and the length ofthe tract captured internal of the implant is compressed completely, theclose approximation of tissue aids in the healing process.

The implant and delivery system is compatible with current surgicaltechnique.

Upon completion of the surgeon preparing the tissue tract, the devicedrain is attached to the rectal end of the fistula probe or seton/suturethat was used to localize the tract.

The probe/seton is pulled toward the surgeon through the fistula tractout of the external opening until the large distal portion of theimplant is abutted against the rectal wall. The Implant coil is alignedto be concentric to the internal tract opening.

The device drain is tied to the fistula probe or localization seton.

In one embodiment the drain seton runs distal of the implant and throughthe length of the handle and may be anchored in the proximal portion ofthe drive shaft or handle.

At the interface of the implant and driver a cutting mechanism (such asa snip, guillotine or the like) may be provided to automatically cut thedrainage seton once the implant is delivered. The handle/delivery systemmay then be readily removed from the surgical field.

In another embodiment the drain seton is locked to the handle/drivermechanism during implantation (delivery of implant) to maintaintraction. Once the implant is fully implanted the handle is decoupled(automatically or manually) from the drain seton. The excess drain setonmaterial may be trimmed at the external surface of the closed tissuetract site at the surface of the rectum.

Referring to FIGS. 72 and 73, a seton 905 is held in a fixed positionalong the length of the tissue tract 901 due to the compression at theinternal opening 902. The implant opening 903 compresses the tissueopening 904 around (onto) the drain seton 905, locking it into place.The drain seton may have a specialty designed/located compression zoneand may have corresponding features to facilitate the anchoring of theseton in this zone 906.

The drain is fixed in place due to the compression forces of theinternal tissue tract being compressed inwardly by the radial forcesapplied by the implant.

To further enhance fixation of the drain seton and prevent the drainseton from moving out of the tract distally or proximally the drainseton may be constructed with locking features 906 along the entirelength, partial length, and defined/predetermined compression zone atthe site of the implant tissue compression, or any combination of these.

Referring to FIG. 68, knots 501 may be implemented along the length ofthe drain seton 502 or at a specific location such as that of theimplant compression zone.

Referring to FIG. 69, spheres, cylinders, triangles and othermultifaceted shapes 602 may be provided such as by moulded over alongthe length of the drain seton 601 or at a specific location such as thatof the implant compression zone.

Referring to FIG. 70, enhance the anchoring of the drain seton barbs703, 704 may be incorporated along the length of a drain seton 702 or ata specific location such as that of the implant compression zone. Thebarbs may face in both the external 703 and internal opening directions704 to prevent motion in either direction.

To enhance the anchoring of the drain seton quills such as 801, 802, 804(FIG. 71) may be incorporated along the length of the drain seton 803 orat a specific location such as that of the implant compression zone. Thequills may face in both the external 802 and internal opening direction801 to prevent motion in either direction.

The drain seton maybe be constructed to act purely as a drain and/or asa scaffold to enhance tissue healing.

To provide enhanced drainage, the seton may have a plurality ofperipheral holes and may include (pores). The shape of the seton incross section may be selected from one or more of round, oval, star andcross. The drain/seton is constructed to be bioabsorbable.

An example of potential materials include: PLA and PLGA(poly(lactic-co-glycolic acid)) (PLGA, PCL, Polyorthoesters,Poly(dioxanone), Poly(anhydrides), Poly(trimethylene carbonate),Polyphosphazenes), and or natural bioabsorbable materials may includefibrin, collagen, chitosan, gelatin, Hyaluronan are bioabsorbablepolymers and would be a material of choice as they are commonly usedbioabsorbable materials.

The shape is designed to enhance the drainage of the residual tract. Theshape may also act as a scaffold to improve/enhance the healing of thetract.

The plurality of peripheral holes/pores enhance drainage of the tract toprevent the drain/seton from blockage.

To enhance scaffolding, the plurality of peripheral holes/pores mayserve as a structure of a scaffold that enhances tissue integration andimproves wound healing of the tract.

A variety of materials may be used as a tissue scaffold that enhance andimprove tissue wound healing. Many of these materials are bioabsorbablepolymers or natural tissue materials. An example of potential materialsinclude: PLA and PLGA (poly(lactic-co-glycolic acid)) (PLGA, PCL,Polyorthoesters, Poly(dioxanone), Poly(anhydrides), Poly(trimethylenecarbonate), Polyphosphazenes), and or natural bioabsorbable materialsmay include fibrin, collagen, chitosan, gelatin, Hyaluronan arebioabsorbable polymers and would be a material of choice as they arecommonly used bioabsorbable materials.

The invention also provides a mechanism to stabilise the tissue duringthe delivery of the implant to prevent bunching and twisting of themucosal layer during delivery of the implant. By preventing such tissueinteraction, the delivery forces may be reduced and a more reliable andrepeatable depth of delivery may be achieved.

One mechanism of stabilising the mucosal tissue is achieved by utilisinga hollow ‘trumpet, cone, shield or pyramid’ type element that isattached to the delivery mechanism and surrounds the undeliveredimplant. One such stabiliser 952 is illustrated in FIGS. 74 and 75.

The ‘trumpet’ interfaces onto the surface of the mucosal lining and maystabilise the tissue prior to and during the delivery of the implantusing one or more of the following mechanisms:

-   -   Pressure—the trumpet may be spring loaded (953) or otherwise to        apply pressure to the mucosal surface. The pressure may be        manual force from the user's application of the delivery        mechanism while abutting to the mucosal surface    -   Spike type features. The surface of the trumpet that interfaces        to the mucosal surface (954) may contain features that penetrate        into the mucosal surface and hence prevent rotation or twisting        of the mucosal lining. These features may be in the form of:        -   Needles        -   Microneedles        -   Micro-spikes (951)        -   Castellated features (similar to the features of a rook in a            chess set)    -   The features may be incorporated into the trumpet by means of:        -   Overmoulding        -   Injection moulding        -   Press fit    -   Surface treatment        -   Rubberized surface        -   Surface modification        -   Surface roughening (sand blasting etc.).

Referring to FIGS. 76 to 79 there is illustrated a system comprising aguide or driver 1101 which in this case is in the form of a coil, and animplant element 1102. In this case the guide coil 1101 is hollow and ismade of a rigid material and contains the implantable element 1102. Theimplantable element 1102 may be made of a malleable material and mayalso be bioabsorbable. The guide coil 1101 has a sharp tip 1103 tofacilitate penetration into tissue. The sharp tip 1103 may be solelypart of the guide 1101, or a part of the guide 1101 and implantableelement 1102 or solely the implantable element 1102.

The guide coil 1101 has a distal diameter that is larger than the tissuedefect such that, in use, the guide 1101 surrounds the internal openingof the fistula track FIG. 78. The guide coil 1101 is driven into thetissue, surrounding the internal opening of the fistula tract 1104 to adepth to below the tissue mucosa 1105 to capture the appropriate amountof sphincter muscle tissue. Once at depth, the guide 1101 is unwoundfrom the tissue leaving the implantable element 1102 anchored in thetissue and surrounding the fistula tract (FIG. 79).

With the guide 1101 removed from the tissue and the implantable element1102 anchored in the tissue, the implantable element 1102 is activatedin this case by pulling in the direction of the arrow 1106. The implant1102 is anchored distally in the tissue and collapses and compresses thetissue tract closed (like a purse string or boa constrictor snake) FIG.79.

The guide coil 1101 may be a straight or tapered coil. The coil may behollow or a rail type support or an internal support (such as aremovable wire internal to a hollow implant element).

The implant element 1102 may be anchored in various ways. A single, (ormultiple), barb 1107 or locking feature may be located at the distal endof the implant element 1102. The barb(s) 1107 allow the implant element1102 to penetrate the tissue in one direction FIG. 80, but when pulledin the opposite direction the barbs 1107 catch and lock the implant inplace FIG. 81.

The anchor can be an “umbrella shape” or “parachute” shape element 1108that is attached to the distal end of the implant element 1102. The“parachute” is initially stowed during delivery (FIG. 82) and isunfurled upon the driver element's extraction (FIG. 83). The largesurface area of the parachute 1109 captures the tissue at the point ofanchorage, locking the implant element 1102 in place.

Multiples of small “hair” like filaments 1110 may be provided along alength of the distal surface covering the full circumference, specificquadrants, and or intermittently covering the distal surface of theimplant element 1102. This quill-like configuration increases thesurface area of the distal end and anchors the implant element 1102 inthe tissue. The bristles or quills 1110 are initiallycollapsed/compressed when stowed in the driver guide (FIG. 84). When theguide is removed from the tissue the bristles are exposed and lock intothe surrounding tissue (FIG. 85).

In some cases the implant element 1102 does not have an anchor. In thiscase the implant element 1102 may be positioned by a pusher 1111 duringremoval of the guide mechanism after delivery to the desired location(FIG. 87).

The implantable element 1102 may be at least partially bioabsorbable.The element may comprise a suture which is anchored distally intotissue. When the guide 1101 is removed, the suture can be pulledproximally and will then cinch the tract closed, similar to a pursestring.

The implant element can be made of a shape memory material such asNitinl or a shape memory polymer. It can be active (requires a stimulussuch as electrical, mechanical, light, magnetism or the like) or passive(heat set).

The implant element 1102 may be stowed in the guide element 1101 fordelivery into the tissue. Once the guide/driver element reaches thedesired depth, the guide element is unwound from the tissue. As theguide is unwound from the tissue the anchored implant is no longersupported by the guide and the exposed portion(s) of the implant is freeto compress the tissue tract. The passive shape set implantable elementcompresses the tissue tract as the guide element 1101 is unwound fromthe tissue. The implantable element 1102 may be preset in shape beforestowage in the guide element 1101. For example, a Nitinol coil is shapeset into the compressed state and is then inserted into the guide 1101.

The implantable element 1102 may be stowed in the driver/guide element1101 for delivery into the tissue. Once the guide element reaches theappropriate depth the guide 1101 is unwound from the tissue leaving theimplant element 1102 anchored in tissue. With the guide element 1101removed from the tissue the implantable element 1102 is then activatedby any suitable means such as heat, light, electrical signal, changingthe state of the implantable element and activating the implantableelement to be transformed to the compression state, thus compressing thetissue tract closed. The patient's body heat may passively activate theimplant element to transform to the compressive state.

A sharp tip may be provided at the distal tip to penetrate into thetissue as the guide/delivery mechanism is advanced into the tissue.

In one configuration the distal tip and leading edge of the coilguide/driver element 1101 has a sharp tip that facilitates thepenetration of tissue upon insertion and during advancement throughoutthe tissue FIG. 76, 1103. The implant element 1102 can pass through thesharp tip when correctly located in the tissue.

In another configuration (FIG. 88) the implant element may have a sharptip 1112 at the distal end that facilitates the penetration of tissueupon insertion and during advancement throughout the tissue

A sharp tip in some cases may be incorporated into both the driverelement and the implant element.

In some cases the implant element is an activatable element which mayhave a collapsed delivery configuration, a deployed configuration, andan activated configuration. The activatable implant element in somecases is an expansile element such as a balloon.

FIGS. 90 and 91 illustrate a coiled balloon 1201 used for closing theinternal opening of a fistula tract. The balloon 1201 is delivered in acoiled manner around the fistula tract 1104 (FIG. 90).

The balloon 1201 may be mounted in a rail of memory alloy or similarwhich assists in forming the spiral balloon shape, on deployment.

In one embodiment the balloon 1201 forms a straight coiled structureafter delivery around the fistula tract.

In another embodiment the balloon 1201 forms a tapered coiled structureafter delivery whereby the larger coil of the balloon is positioneddeeper in the tissue than the narrow end.

The balloon 1201 may be delivered using a hollow delivery coil whichlocates the balloon in place. The balloon is then pushed out of thedelivery coil and left in place.

Once in place, the balloon 1201 is inflated with saline, or other liquidor gas 1203 (FIG. 91). The effect of inflation is to compress the tissuesurrounding the fistula tract 1202 thereby closing the internal openingof the fistula tract. This compression provides an effective sealagainst the pressures generated in the rectum and prevents passingfaeces entering into the fistula tract, thus preventing re-infection.

The balloon may be comprised of a bioabsorbable material or similar.After a period of time corresponding to the healing of the fistulatract, the balloon material may degrade to a sufficient extent that thefluid with which it is filled (e.g. saline) is exposed to the tissue andis also absorbed. In time the entire balloon is absorbed.

The delivery mechanism may have a sharp tip to facilitate progressionthrough the tissue.

The balloon may be dragged behind a coiled solid needle type deliverymechanism and detached to deploy the balloon.

In another embodiment the balloon is made from a non-bioabsorbablematerial, and is removed at an appropriate time frame post healing ofthe fistula tract.

The pressure to which the balloon is inflated may be variable. Theballoon may be inflated to a pressure that corresponds to sufficientclosing of the tract opening thereby overcoming the variability indelivery, anatomy and tract diameter.

A programmable electronic controller may be used to automaticallyinflate the balloon to the appropriate pressure.

Alternatively an analog or digital pressure gauge may be provided toindicate the balloon pressure to the clinician.

The activatable compressive element (balloon) may similarly be formedfrom a foam, pre formed structure (e.g. Nitinol cage or stent-likestructure), or collapsible coil or other similar structure.

Referring to FIGS. 92 and 93 the implant element 1301 can be made from ashape memory material (Nitinol, shape memory polymer composite)activated by heat, light, electrical current or other energy source.

Once the implant element 1301 is delivered to the desired depth by anappropriate delivery/guide element 1302 (FIG. 92) the implant 1301 isactivated by heat, light, electrical signal or other method, changingthe state of the implant 1301 and activating the implant to betransformed to the compression state, thus compressing the tissue tractclosed 1303 (FIG. 93). The patient's body heat may passively activatethe implant to transform to the compressive state.

A compression coil may be delivered by placing a delivery tube 1401 aspecified distance from the internal opening of the tissue tract (FIG.94). Inside the tube an implant element 1402 is stowed. The deliverytube is inserted to the desired depth and the implant coil is forced outof the tube. As the implant coil exits the tube opening (FIG. 95) thesuccessive diameters of the coil surround the tissue tract and compressthe tissue resulting in closure of the tract.

In another embodiment (FIGS. 96, 97) each additional coil of the implantelement 1403 is smaller in diameter aiding in compressing the tract andachieving closure.

The coil can be made of a shape memory material. It is delivered as astraight coil and upon activation it compress the tissue tract.

In another method, the implant material is not shape set and not of ashape memory material but is formed by a die built into the deliverytube (FIG. 98). As the coil exits the delivery tube and passes throughthe die 1404 the implant coil is formed on demand. The coils producedsurround the tissue tract and compress the tract.

Referring to FIGS. 99 to 103 the implant element 1406 may also bedelivered through a delivery mechanism 1405 located at the mucosalsurface resulting in a ‘winding’ around the fistula tract tending tocreate a compression zone 1407 and resulting in closure of the tract.The implant may be preformed in a straight or tapered configuration. Theimplant element may have a sharp tip 1408 to facilitate progressionthrough the tissue.

In some cases the implant may comprise a plurality of elements 1500. Onesuch implant is illustrated in FIGS. 104 and 105. The multiple elementsbe delivered individually surrounding the fistula tract.

Each element may be preformed, or formed on delivery, or be activatableas previously described. The elements may be the same size in thepreformed, or activated state. Alternatively the leading element may belarger in diameter and the following elements progressively smaller.

The clinician may determine the number of elements to deploy to attainadequate closure of the tract.

The device is capable of one or more of the following:

-   -   accommodating varied fistula tract physiology;    -   occluding and sealing the internal opening of the tract;    -   preventing faecal matter re-infecting the tract;    -   preserving sphincteric function;    -   enhancing fistula tract healing; and    -   facilitating drainage during healing.

The perianal fistula treatment device ensures sparing of the sphincter,occluding of the fistula tract internal opening, and promotion ofdrainage and tissue healing.

The anchoring and sealing mechanism of the device may consist of atapered coil. The coil geometry is designed to pull tissue together asit is deployed into the sphincter muscle complex, resulting in a stronganchor but also, importantly, an effective compressive seal preventingreinfection of the fistula tract and close tissue approximation toenhance tissue healing.

The perianal fistula treatment device preserves sphincteric andanatomical conditions and functions, prevents re-fistulisation, andimproves healing time over the current treatment methods. The implantcloses the fistula internal opening by compressing the tract'ssurrounding tissue inwardly such that the tissue is brought within closeapproximation creating a seal impermeable to foreign materials andpromoting tissue growth across the closely approximated fistula tract.

A drain may be used to provide a conduit to drain any abscess andremaining or newly formed exudate and fluids from the fistula tractthroughout the time of the healing process. Such a drain or seton may beany of those described above.

The implant may be of any suitable shape in transverse cross section.For example, the implant cross-section may be round, oval, triangular,multifaced or ribbon-like. In some cases the implant may be hollow.

The implant may be intended for subsequent removal or may bebioabsorbable.

Typical materials for the implant include

-   -   Bioabsorbable magnesium (including MgFe and other magnesium        alloys) would be a material of choice because it offers the        strength of stainless steel and similar metals, yet is        bioabsorbable. MgFe alloys are well studied and have been used        in medical products.    -   PLA) and PLGA (poly(lactic-co-glycolic acid)) are bioabsorbable        polymers and would be a material of choice as they are commonly        used bioabsorbable materials and have been well studied and used        in medical products for over 70 years.    -   The implant may also be constructed from other common materials        used for suture applications

A bioabsorbable implant would be beneficial to treatment of perianalfistulas due to the body's natural tendency to reject foreign materials.

The closure implant of the device may be maintained during the entirehealing process. In some cases the implant remains in situ to withstandrectal pressures and maintain closure of internal tract opening for atleast 10 weeks to prevent re-opening of the tract.

The implant may remain in place longer to allow full healing of theinternal opening of the fistula tract.

The implant remains in place for a long enough period of time (e.g.greater than 1 week) to allow remodelling of the defect in the mucosaand formation of a mucosal layer. This mucosal layer acts as a bacterialseal preventing reinfection of the tract from entering of fasces. Thereformation of the musical layer in conjunction with the sphinctermuscle closure mechanism prevents fasces entering the tract.

The implant may be doped or loaded with healing and antimicrobial agents(such as stem cell, silver ions, silver particles, antibiotics,antibacterial agents and the like).

Modifications and additions can be made to the embodiments of theinvention described herein without departing from the scope of theinvention. For example, while the embodiments described herein refer toparticular features, the invention includes embodiments having differentcombinations of features. The invention also includes embodiments thatdo not include all of the specific features described.

The invention is not limited to the embodiments hereinbefore described,which may be varied in construction and detail.

The invention claimed is:
 1. A method of treating a perianal fistulawith a helical implant having a proximal end and a distal end, theperianal fistula having an internal opening from the rectum, an externalopening in an external surface of a buttocks, a fistula tract extendingbetween the internal opening and the external opening, and fistulatissue surrounding the fistula tract, the method including: engaging thedistal end of the implant about the internal opening before the proximalend of the implant, advancing the implant toward the external opening tocompress fistula tissue via the implant, and embedding the proximal endof the implant in the fistula tissue such that none of the implant isexposed to the rectum, the proximal end of the implant compressing thefistula tissue more than the distal end of the implant, and the implantsealing closed the internal opening of the fistula tract while leavingopen the external opening of the fistula tract.
 2. The method of claim1, wherein the sealing includes sealing against pressure of up to 150mmHg.
 3. The method of claim 1, wherein the sealing includes sealingagainst pressure of up to 200 mmHg.
 4. The method of claim 1, whereinthe embedding of the proximal end of the implant includes embedding theimplant below a mucosal lining and into a sphincter muscle complex. 5.The method of claim 1, further including locating a drain within thehelical implant so that the compression of fistula tissue via theimplant compresses tissue about the drain.
 6. The method of claim 1,further including embedding a proximal end of a drain in a sphinctermuscle complex, and a distal end of the drain protrudes through theexternal opening.
 7. The method of claim 1, further including extendinga drain through the fistula tract and using the drain to position theimplant about the internal opening prior to advancing the implant. 8.The method of claim 1, wherein, following the compressing, a majority ofthe fistula tract remains open.
 9. A method of treating a perianalfistula with an implant having a proximal end and a distal end, theperianal fistula having an internal opening from the rectum, an externalopening in an external surface of a buttocks, a fistula tract extendingbetween the internal opening and the external opening, and fistulatissue surrounding the fistula tract, the method including: forming aperianal sinus by cinching closed the internal opening with the implantby advancing the implant distally through fistula tissue toward theexternal opening, wherein the implant tapers in a distal to proximaldirection, and drawing fistula tissue radially inwardly, wherein a firstregion of fistula tissue is drawn radially inwardly to a greater extentthan at least a second region of fistula tissue, wherein the firstregion is closer to the internal opening than the second region.
 10. Themethod of claim 9, wherein the forming the perianal sinus includesrotating the implant to embed the implant into bulk tissue of asphincter muscle complex.
 11. The method of claim 9, wherein therotating of the implant includes advancing the proximal end of theimplant to immediately past a mucosal lining of the rectum.
 12. Themethod of claim 9, wherein the taper is defined by an outer surface ofthe implant.
 13. The method of claim 9, further including positioning adrain within the fistula tract, wherein at least a portion of the drainextends from a location within the fistula tract and through theexternal opening.
 14. The method of claim 13, further includingembedding a proximal end of the drain in a sphincter muscle complex. 15.The method of claim 9, wherein the forming of the perianal sinus furtherincludes forming a seal against pressure of up to 150 mmHg.
 16. A methodof treating a perianal fistula with an implant having a proximal end anda distal end, the perianal fistula having an internal opening from therectum, an external opening in an external surface of a buttocks, afistula tract extending between the internal opening and the externalopening, and fistula tissue surrounding the fistula tract, the methodincluding: contacting the fistula tissue with the implant about theinternal opening, wherein the implant includes a coil having a pluralityof coil loops extending between the proximal end and the distal end,wherein at least a portion of the coil tapers in a distal to proximaldirection along a length of the coil between the proximal end and thedistal end; rotating the implant into fistula tissue, distal end first,to advance the distal end of the implant toward the external opening,causing a diameter of at least a portion of the fistula tract to closevia the tapered portion; and facilitating drainage through the externalopening after the implant is in place.
 17. The method of claim 16,further including compressing fistula tissue via the implant, whereincompressing includes progressively compressing fistula tissue such thata compression force imparted to fistula tissue via the distal end of theimplant is less than a compression force imparted to fistula tissue viathe proximal end of the implant.
 18. The method of claim 16, furtherincluding, embedding the proximal end of the implant below a mucosallining and into a sphincter muscle complex.
 19. The method of claim 16,further including positioning a drain so that the closed portion of thefistula tract secures the drain, and at least a portion of the drainextends from the fistula tract and through the external opening.
 20. Themethod of claim 19, wherein at least one of the implant or the drain arebioabsorbable.
 21. The method of claim 20, wherein both of the implantand the drain are bioabsorbable, and wherein a rate of absorption of thedrain is faster than a rate of absorption of the implant.
 22. A methodof closing a perianal fistula forming an opening in tissue comprising:delivering a helical implant distally into tissue such that a pluralityof helical loops of the implant pass through tissue surrounding theperianal fistula and compress tissue radially inwardly; and fixing adrain relative to the implant such that after the implant is deliveredthe drain extends from within the opening to a location outside of theopening, the drain being configured to facilitate fluid drainage fromthe opening along the drain, wherein fixing the drain relative to theimplant includes compressing tissue radially inwardly about the drain.23. The method of claim 22, further including drawing tissue around theopening radially inwardly toward a center of the implant, wherein aproximal region of tissue within the implant is drawn radially inwardlyto a greater extent than a distal region of tissue within the implant.24. The method of claim 22, wherein the implant comprises a tapered coilportion tapering toward a proximal end of the coil.
 25. The method ofclaim 22, further including sealing closed only one end of the opening.26. The method of claim 22, further including engaging a non-tapereddistal section of a delivery device with an external surface of theimplant.
 27. The method of claim 22, further including advancing aproximal end of the implant below a mucosal lining and into a sphinctermuscle complex.
 28. A method of closing a perianal fistula in tissue,the fistula having an internal opening and an external opening,comprising: delivering a helical implant distally into tissue such thata plurality of helical loops of the implant pass through tissuesurrounding the perianal fistula and compress the tissue radiallyinwardly, wherein a proximal portion of the implant radially compressesthe tissue more than a distal portion of the implant; deploying theimplant in an implanted position wherein a proximal end of the implantis completely embedded in the tissue; and fixing a drain relative to theimplant such that, after the implant is delivered, the drain extendsfrom within the fistula to a location outside of the external opening,the drain being configured to facilitate fluid drainage from theexternal opening along the drain.
 29. The method of claim 28, whereinthe embedding includes embedding the implant below a mucosal lining andinto a sphincter muscle complex.
 30. The method of claim 28, wherein thefixing of the drain includes compressing tissue about the drain as aresult of the deployment of the implant.